The challenge of speed in transmission through a network is continuous. Remote operators desire near real time reception of a transmitted signal. Many remotely operated apparatuses may require near immediate network speeds such that time is critical to ensure apparatus success and general safety. Current network latency values may exceed those required for safe and effective operation of time critical manipulation of a remotely operated apparatus
As an example, latency values of 50-100 milliseconds (ms) may be considered standard or average as found in many pathways through, for example, an INTERNET connection. A routine speed test run on a desktop PC connected to the INTERNET via an ETHERNET connection may yield in the range of 60-70 ms. These transmission speeds may prove too slow to accommodate a time critical operation of a remotely controlled apparatus. For example, a surgeon remotely operating on a patient or a pilot controlling an aircraft may require input and any feedback at a faster rate (e.g., less than 30 ms).
Current latency reduction systems and apparatus provide insufficient latency reduction for the safe operation of remotely controlled vehicle and surgical apparatus. Remotely controlled mission critical devices require onsite direct control characteristics. Such onsite direct control characteristics are particularly elusive where communication is interposed over a web-based network where any of a number of pathways will have varying transmit and receive times. Different pathways for different packets produces unpredictable transmit and receive times with over-all average latencies in excessive of those necessary for predictable and safe operational results. For example, during a landing flare, latency may cause operator inputs to induce out-of-sync control to aircraft pitch attitudes causing porpoising generally resulting in remote vehicle destruction. Control inputs are often intended to overcome a previous over control (excessive) control input. Such inputs are intended to produce destructive rather than constructive harmonics. Where feedback arrives too long after a control input an operator seeking to finesse/operate/control an aircraft (apparatus) into a desired angle of attack or position (for example) may instead exacerbate the condition/problem. Such instances may very quickly devolve into an unrecoverable condition.
U.S. Pat. No. 6,556,560 to Katseff, et al. attempts latency reduction through “downsampling the data rate to equal an interim data rate.” Katseff reduces latency at a conversion stage from analog to digital through increased sampling rate at the transmission end to “fill” the buffer more quickly with higher fidelity data allowing a lower latency value through the buffer. The same is done on the receiving end to reduce time delay through the buffer. Katseff's method however, does not address the latency values found from end to end in a transmission through a network.
U.S. patent application Ser. No. 12/603,224 filed Oct. 22, 2009 by Ohbitsu discloses a device for reproduction of missing signals. This signal transmission and reception device may detect missing signals at a receiving end and interpolate from the received signals to find the missing signals. The method disclosed by Ohbitsu does not increase the address the speed or likelihood a packet of data will reach a destination in a mission critical environment.
U.S. patent application Ser. No. 11/969,219 filed Jan. 3, 2008 by Menn et al. discloses a method of packet loss mitigation using predictive multisending of data based on an analysis of invariant and variable parameters associated with data transmission. Menn discloses however, sending duplicates of every packet may increase processing times and/or overload the network.
Noon “Missing Packet Recovery Techniques for Low-Bit-Rate Coded Speech” by Suzuki and Taka published June 1989 summarizes various techniques including substitution, interpolation, and Linux Standard Bus (LSB) dropping. The authors found LSB-dropping as the preferred method of missing packet recovery as scored by listeners. The disclosure is limited audio post-reception techniques and fails to address full end-to-end latency.
“A New Sample-Interpolation method for Recovering Missing Speech Samples in Packet Voice Communications” by Yuito and Matsuo published 1989 (IEEE) discloses a pattern matching method of interpolation to achieve acceptable results during packet loss. As with Suzuki et al., the disclosure is limited to post-reception activity and fails to address latency issues with a signal from transmission to reception.
Consequently, it would be advantageous if a method and device existed capable of transmission of a group of multiple identical packets through a network, the network determining the path in which each individual packet or signal may travel (thereby adding at least a latency or an average latency). The unequal time of travel of each signal being determined by the path chosen for it by the network. The method and device taking advantage of the unequal time each packet may take through the network. The method and device further able to receive the signals and determine the first to arrive of each group of identical signals, save the data included in the first to arrive and ignore the later arriving of the identical signals. The method and device further configured to interpolate to determine a data value if at least one of the identical signals should not arrive within a variable wait time. The waiting time limited to a time less than a time necessary to prevent overall system controlled latency being more than substantially less than the networks average latency. The method and device further configured to manipulate an apparatus at the receiving end using the reconstructed data. The device finally configured to transmit feedback to the user.